1. Technical Field
The present invention relates to a method for controlling semiconductor manufacturing equipment and a system for controlling the equipment, and particularly to a technology to control amounts of electric power and other energy consumed in a waiting mode in which product processing is not carried out depending on the length of waiting time.
2. Related Art
A production line of semiconductor devices has a clean room that makes filtered clean air flow down and various manufacturing equipment arranged in the clean room. Examples of the manufacturing equipment include a diffusion furnace that makes thermal diffusion of an impurity in a semiconductor wafer, a CVD device that provides an insulating film, and a dry etching device that etches an insulating film or a conductive film. Most of the equipment requires not only the electric power but also the other energy, such as evacuated air, cooling water, compressed air, vacuum, nitrogen (N2) and released heat.
While manufacturing equipment is in a waiting mode between product processes, power supply from a radio-frequency power source and a magnetic power source is cut and the output of a heater is reduced to some extent to cut down on energy use in related art. The manufacturing equipment stays in the waiting mode at a level at which product processing can be restarted as soon as a product to be processed next is provided to a loader of the manufacturing equipment (i.e., level at which product processing is ready) so as not to prevent reduction in turnaround time (TAT).
There has been another method to reduce power consumption that uses manufacturing equipment (e.g. coater developer) having a plurality of units providing a semiconductor wafer with different processes. The equipment does not supply electric power to the units in the waiting mode. JP-A-2003-282465 is an example of related art.
Related technologies have been developed not only in the field of electronic devices but in the field of office automation equipment. For example, power consumed by an image forming device like a printer can be reduced by shifting to a power-saving mode automatically after the device comes out of the power-saving mode and forms images. JP-A-2002-120435 is an example of related art.
In general, a production line handles not one type of product but multiple types of products in small lots. Different product types require different product processes. Accordingly, some manufacturing equipment in a production line is frequently used, and the other is not. Furthermore, the frequency of the use of manufacturing equipment varies depending on product types, volume and process timing on a production line in general.
It is therefore rare to keep operating the manufacturing equipment until a predetermined maintenance break. In many cases, the equipment stays in a waiting mode between product processes. The waiting time between product processes may be for several minutes or last a couple of days.
However, related-art manufacturing equipment making up a production line in a waiting mode always stays at a level at which product processing is ready regardless of the length of waiting time before the next product processing. Therefore, a long waiting time causes a large energy loss.